My long distance gf has a guy best friend in her hometown who is a professional photographer. I haven't met him in person yet. They were out together yesterday for a festival and he posts on Facebook some high quality photos of her and other friends there he has taken, most of them including only my gf. They are nothing explicit, just my gf smiling or posing, some including from the top where you can see her cleavage. I also observe that he shares songs on her wall frequently.
I also have close female friends and I am comfortable with her having guy friends. But since I haven't met him in person and there is distance between, I am not comfortable seeing her posing to another guy I don't know. To be honest, I became extremely jealous when I have seen them.
I know I should trust her and even appreciate that how beautiful she looks in those photos but I have no idea how I should get into that mentality. What would a confident man unlike me would do when he has seen those photos? What is a good way to calm down?